Tempering of sheet material



April 14, 1959 G. WHITE 2,881,565

TEMPERING 0F SHEET :MATERIAL Filed June 14, 1955 3 Sheets-Sheet 1 1INVENTOR. y BY fimfld 3M6 em e A TTORNEYS April 14, 1959 G. WHITE2,881,565

' TEMPERING 0F SHEET MATERIAL Filed June 14, 1955 v 3 Sheets-Sheet 2 5&4

1'- J .5 INVENTOR.

B z066egdtd0/1e A TTORNEYS April 14,- 1959 G. WHITE 2,881,565

TEMPERlNG OF SHEET MATERIAL Filed June 14, 1955 5 Sheets-Sheet 3 I I]! HII IN V EN TQR. 2 5M444 /Me ATTORNEYS United States Patent TEMPERING FSHEET MATERIAL Gerald White, Rossford, (lhio, assignor to Libbey-Owens-Ford Glass Company, Toledo, Ohio, a corporation of Application June 14,1955, Serial No. 515,275

6 Claims. (Cl. 49-45) The present invention relates broadly to'thetempering of sheet material and more particularly to an improved methodand apparatus for tempering glass sheets on plates.

It is common practice in the tempering of glass sheets to first heat thesheets to substantially the point of softening of the glass and then tosuddenly chill the heated sheets to place the outer surfaces thereofunder compression and the interiors thereof under tension. By thismeans, the mechanical and heat resistance characteristics of the sheetsmay be changed.

The method and apparatus of the invention may be used to treat varioustypes of flat or curved sheet material and in the production ofelectrically conductive films on glass articles as described in Patent2,429,420 to H. A. McMaster, issued October 21, 1947. However, it willbe described primarily with relation to the tempering'of bent or curvedglass sheets and has as its primary object the provision of a novelmethod and apparatus for evenly tempering bent glass sheets or the like.

Another object of the invention is to provide means of obtaining a moreefficient use of the tempering cooling medium so as to impart greatertempered strength to thin glass sheets than has heretofore been possibleby previous methods.

A still further object of the invention is to arrange the nozzlesthrough which the cooling medium passes to the sheets so as to conformas nearly as possible to the shape of the sheets.

A still further object of the invention is to provide a novel means ofdirecting the cooling medium or fluid from the nozzles along a pathsubstantially parallel with v the direction of movement of the sheets.

Other objects and advantages of the invention will become more apparentduring the course of the follow ing description when taken in connectionwith the accompanying drawings.

In the drawings, wherein like numerals areemployed to designate likeparts throughout the same:

Fig. 1 is a plan view of the equipment for carrying out the inventionshowing the general arrangement of various components thereof;

Fig. 2 is a side elevation of the tempering apparatus of the invention;

Fig. 3 is a front elevation of the entrance end of the temperingapparatus shown in Fig. 2;

Fig. 4 is a sectional view taken substantially along lines 4-4 of Fig. 2showing a bending mold passing through the tempering apparatus;

Fig. 5 is a fragmentary detail view of a typical nozzle of theinvention;

Fig. 6 is a plan view of the tempering apparatus of the inventionincluding a fragmentary section of the central manifold;

Fig. 7 is a fragmentary perspective view of a portion of the nozzles-ofthe invention; and v Fig. 8 is a schematic showing of a flow-pattern ofthe 2,881,565 Patented Apr. 14, 1959 ice cooling medium flowing throughthe nozzles of the invention.

With reference now to the drawings and particularly to Figs. 1 and 2,molds of the type indicated generally at 10 in Fig. 4 carrying glasssheets S to be bent and tempered are started along a power conveyorsection 11 which extends through a furnace or heating chamber 12 andcarries the molds into the inlet end 12 thereof. At the discharge end 13of the furnace 12 the molds are carried on narrow chain conveyors 14 and15 which pass along the sides of a quenching or tempering station 16 andpermit the mold to straddle a lower portion of the quenching system.

From the chain conveyors 14 and 15 the molds are transferred to anotherconveyor section 17 leading to a semi-circular conveyor section 18 whichreverses the direction of travel of the molds and leads them to a returnconveyor 19 extending alongside the heating chamber 12 and terminatingat an unloading station 20. The bent glass sheets, which have now cooledto a temperature at which they may be handled, are removed from themolds at the unloading station 20 and the molds are then carried on asemi-circular conveyor 21 to a loading station at the start of theconveyor 11.

Referring now particularly to the quenching or tempering system 16, thissystem includes a lower blast-head 22 (Fig. 3) and an upper blast-head23 through which a suitable cooling medium such as air may be directedto the sheets as they pass thereby. More particularly, the upperblast-head 23 is mounted above the path of the sheets on a framestructure which includes uprights 24 and cross beams 25, while the lowerblast-head is supported on suitable I-beams 26 (Fig. 4) below the pathof the sheets.

Dealing now specifically with the lower blast-head 2 as may best be seenin Figs. 2, 3 and 4, it includes a plurality of transversely extendinglower manifolds or headers 27 supported on and between the I-beams 26.Extending upwardly and between the central portions of the manifolds 27are a plurality of longitudinally extending central nozzles 28preferably arranged to follow the general central contour of the bentsheet S on the mold 10.

Each of the nozzles comprises a bottom wall 29 (Fig.- 5), side walls 30having converging side portions 31 and transverse end walls 32. Theconverging side wall portions 30 define a longitudinal slot or orifice33 (Fig. 7) therebetween at the extreme ends of the nozzles throughwhich the cooling medium may pass and be directed to the lower surfaceof the sheets passing thereby. Cooling medium may be supplied to therespective nozzles through suitable openings 33' formed in the bottomwalls 29 of the nozzles which mate with corresponding opening in therespective manifolds. This cooling medium may be brought to themanifolds by pipes or conduits 34 connected to a suitable source notshown.

Secured to and extending upwardly between the respective lower manifoldsand along the outer edges thereof are ducts indicated generally at 35(Fig. 4) which at their upper ends carry a plurality of angularlydisposed longitudinally extending nozzles 36 adapted to direct thecooling fluid to the extreme curved ends of the bent glass sheet S onthe mold 10. These nozzles 36 are similar in construction to the lowercentral nozzles 28 and may be oriented to conform to the general contourof the bent end portions of the sheet so as to direct the cooling mediumsubstantially-evenly over the lower surface thereof. The cooling mediumis supplied to the ducts through suitable openings provided in each ofth respective lower manifolds 27. Y Turning now to the upper blast-head23, it is formed in a manner'substantially similar to the lowerblast-head 22 and includes transversely extending manifolds or headers37 mounted on the frame cross beam 25. Centrally disposed nozzles 38extend'between the respective manifolds in a direction substantiallyparallel to the direction of movement of the sheets and are connected tothe upper manifolds 37 through slots or openings 39 as shown in Fig. 6.The upper central nozzles, similar in design to nozzles 28 and 36, areconvex downwardly to substantially conform to the central curvature ofthe mold and bent sheet S and may be staggered with relation to thelower central nozzles 28 to give a more uniform quenching pattern. Inorder to adequately cool the upper curved end portions of the sheet Sthere are provided enlarged end nozzles 40 having three angularlydisposed nozzle tips 41 disposed to substantially conform to the endcurvature of the sheets.

From the above, and with particular reference to Fig. 4, it will beapparent that the upper nozzles 38 and are disposed downwardly along aconvex pattern. while the ends of the lower nozzles 28 and 36 form adownwardly concave pattern so that a clear space is left between thenozzles which conforms generally to the curvature of a bent glass sheetS and the mold 10. The nozzles may in this way be placed substantiallyequidistantly from the surfaces of the glass sheet thus making itpossible for the cooling medium to be directed evenly and atsubstantially the same pressure along all areas of the bent sheets.However, the angular disposition of the nozzles may be changedto.conform to curvatures of various shapes.

If desired, the cooling medium or fluid which emerges from the nozzleorifices in longitudinally extending strips or layers at substantialright angles to the sheet surface may be controlled by the use ofdirectional fins or plates 42 (Fig. 7). These fins 42 may be formed ofbendable metal and according to the preferred embodiment shown in'Fig.7, may be alternately staggered on one side and then the other of thelongitudinally extending orifices 33.

More particularly, as shown in Fig. 7, the directional fins 42 on oneside of an orifice 33, indicated by the numeral 43, may compriseangularly disposed tabs a, b and 0, while the directional fins on theother side of the orifice indicated by the numeral 44 may be spacedlongitudinally from the fins 43 as at d and comprise angularly disposedtabs e, f, and g. Thus, as the cooling medium emerges from a nozzleorifice 31 it strikes the tabs (1, b, and c and e, f, and g and isdeflected in predetermined angularly disposed streams away from itsnormal path toward a sheet so as to sweep the sheet in a predeterminedpattern across its width.

For example, as may be seen in Figs. 7 and 8, the tabs may be bent toprogressively deflect the cooling fluid across the sheet. Asparticularly illustrated in Fig. 8, the cooling fluid striking the tab aof a directional fin 43 will be. deflected to sweep an area a betweenthe projection lines 45and 46; the cooling medium striking tab b willsweep an area b between projection lines 46 and 47; and the mediumstriking tab c will sweep an area c between projection lines 47 and 48.The space d between the fins 43 allows the cooling medium to flowdirectly fromvthe orifice 33 at substantially right angles to thepassing sheet. However, after leaving the orifice area corresponding tothe space d, the cooling fluid diverges and'sweeps the area d betweenprojection lines 48 and 49.

Continuing, tabs e, f, and g of the directional fins 44 deflect thecooling medium in streams to the other side of the areas d as indicatedby the areas .2, f, and g between projection lines 49-50, 50-51, and5152 respectively. As will be apparent from Fig. 8, the quenchingpattern of each of the nozzles may overlap one another as is illustratedby the intersections of the projection line 53 from an adjacent nozzle(not shown). In this way, the passing sheet may be swept across itsentire width. Of course, each of the areas a, b, c, d, ete., swept bythe deflected cooling medium may overlap one 4 another both transverselyand longitudinally of the disposition of the nozzle orifice because ofthe divergence of the cooling medium; this effect further aids in evenlycooling the sheet.

As will be apparent from Fig. 8, the staggered relation of the lowernozzles 28 with respect to the upper nozzles 38 enables cooling mediumto be directed to the sheet in a further overlapping relation asindicated by projec tion lines 53 and 53". In other words, where thereis a space between the upper nozzles 38, a lower nozzle 28 will bedirecting the cooling fluid toward the area from the underside of thesheet. Because of the relative thinness of the sheet, the cooling mediumdirected at one side of the sheet will have a decided cooling effectthrough the entire thickness of the sheet and thus a constant uniformcooling effect over the sheet is obtained. Of course, the temperingpattern can be further finely controlled and adjusted by arranging thelocation of the directional fins and the angular relationship of therespective tabs.

After the cooling medium strikes a passing sheet, it may be exhaustedthrough openings or spaces 54 provided between the respective nozzlesand the manifolds (Figs. 4 and 6). By providing a means of quicklyexhausting or removing the hot expanded cooling medium after it has beendeflected from the hot sheets, a better tempering and quenching patternis obtained over the sheets and less initial pressure is required sinceback pressures which tend to build up along the path of the sheets arereduced enabling the cooling medium to strike the sheet directly and topierce the film of hot cooling medium adjacent the surface of thesheets.

To further facilitate the removal of the hot cooling medium after itstrikes a passing sheet, the lower central nozzles 28 have theirhorizontal bottom walls 29 extending upwardly as at 55 (Fig. 2) so as tooffer less resistance to the exhaust flow. Likewise, the ducts 35 whichmount the lower side nozzles 36 are walls recessed upwardly as at 56 toaid in exhausting the hot cooling medium. For the same purpose, theupper walls 29 of the upper nozzles 38 extend downwardly as indicated bythe dotted lines 57 in Fig. 2.

To protect the glass sheets from uneven cooling and to decrease the heatloss from the furnace, the exit opening 13 of the furnace is providedwith partially closed baflie plates 58 and 59 (Fig. 2) which are spacedfrom one another along a contour that conforms to the end elevation ofthe mold and the glass carried thereon. To further aid in restrictingthe flow of hot gases toward the entry end of thequenching station 16,there are provided deflecting or baffle seats. More particularly, asshown in Fig. 3, the lower central nozzles 28 are provided with anangularly disposed baflie plate 60, while the side nozzles 36 areprovided with bafie plates 61, and the upper nozzles 38 and 41 areprovided with a battle plate 62.

Now, in moving through the tempering station 16 in the directionindicated by arrow x, the molds and the glass sheets S are carried bythe conveyors 14 and 15, each of which includes a conveyor chain 63(Fig. 4) driven by a sprocket 64 mounted on a short cross shaft 65. Thecross shaft 65 at its outer end. is connected to a suitable drivesprocket arrangement indicated generally at 66 which in turn isconnected to transverse power shaft 67 journaled in bearings 68. Thisparticular drive means is more fully described in U'.S. Patent 2,646,647to W. P. Bamford et al. and may be utilized to rapidly move the molds 10from the furnace and into the quenching station, after which, theconveyor speed may be reduced to slowly move the molds through thetempering region.

The conveyor chains 63 of conveyors 14 and 15 during travel along theirupper flight ride on longitudinal wear plates 69 supported on channelirons 70 secured between side channel irons 71 and 72 which togetherwith a base plate 73 form a box-like frame for the conveyor chain.

The return or lower flight of the conveyor chains 63 run on the baseplate 73. Inv this arrangement the upper portion of the side channelirons 71 and 72 serve as side guards to prevent the molds from departingfrom their intended path.

Reviewing now the entire process of the invention bent glass sheets Scarried by the molds 10, which may be of a special hinge type so as toenable them to ride between the respective nozzles as shown in Fig. 4,and are moved along the conveyor section 11 and pass through the heatingfurnace or chamber 12, after which, they are transferred onto conveyorsections 14 and 15 and moved through the tempering station 16. Duringpassage through the tempering station 16 the sheets may be quenched orcooled generally across their entire width by means of the coolingmedium flowing through the longitudinally extending nozzles which may bedirected in a predetermined path by the directional fins or plates 43.These fins, as may clearly be seen from the schematic diagram of Fig. 8,progressively deflect portions of the cooling medium, which emerges fromthe nozzles in strips or layers substantially parallel to the directionof movement of the sheets stepwise away from its normal path so as tosweep the width of the sheet.

After emerging from the quenching or tempering station 16, the molds aretransferred to the conveyor section 17 and moved to the unloadingstation 20 whereupon the tempered sheets are removed and then moved tothe loading station of the conveyor 11 where they will be in position tobegin another bending and tempering cycle.

While one method of tempering and quenching sheet material has beenshown, it will be evident that the cooling medium may be regulated bycontrolling the size of the orifices or by changing the angular positionof the fins or their number and/or position along the length of thenozzles. Moreover, while the sheets have been shown to move while thenozzles remain stationary, it will also be evident that the nozzles maybe moved relative to the sheets, or both the sheets and the nozzles maybe moved relative to one another. Also, of course, other means ofcarrying the sheets may be employed.

It will of course be understood that the invention disclosed herein isto be taken as the preferred embodiment thereof and that various changesin the shape, size and arrangement of parts may be resorted to withoutdeparting from the spirit of the invention or scope of the followingclaims.

I claim:

1. A method of tempering glass sheets or plates by first heating thesheets and then rapidly chilling the surfaces thereof, comprisingdirecting a cooling fluid toward said sheet in the form of a layer,progressively deflecting portions of said layer stepwise at differentangles to one side of the normal path of said layer toward said sheetwhile progressively deflecting alternate portions of said layer stepwiseat different angles to the opposite side of said normal path, andeffecting relative movement between said sheet and said cooling fluid tocause a surface of said sheet to be contacted by said fluid.

2. The method of tempering glass sheets or plates as claimed in claim 1,in which the layer of cooling medium is disposed substantially parallelto the direction of relative movement between the sheet and said layer.

3. In apparatus for tempering bent glass sheets, in combination,conveyor means for carrying molds bearing bent glass sheets thereonalong a definite path, a plurality of elongated spaced nozzles disposedtoward the path of the molds and bent glass sheets, said nozzles havinglong narrow slots therein disposed substantially parallel to the path ofmovement of said sheet through which a cooling medium may pass, andmeans adjacent said slots in said nozzles to progressively deflectportions of said cooling medium stepwise at angles of varying magnitudetransversely of the path of said sheets.

4. Apparatus for tempering sheets or plates, comprising a support forholding a sheet to be tempered, means for directing a fluid coolingmedium onto a surface of said sheet including a slot through whichcooling medium may pass, means for bringing cooling medium to said slot,means for creating relative movement between said sheet and said slot,said slot being disposed substantially parallel to the direction ofmovement between the slot and sheet, and a plurality of deflection finshaving tabs thereon which are angularly disposed with respect to oneanother mounted adjacent said slot for progressively deflecting thecooling medium stepwise at angles of varying magnitude after it passesthrough said slot from its normal path toward said sheet.

5. Apparatus for tempering sheets or plates as claimed in claim 4, inwhich said deflection fins are disposed to deflect the cooling medium toone side and then the other of said slot.

6. Apparatus for tempering sheets or plates as claimed in claim 4, inwhich there are provided a plurality of spaced slots in said directingmeans through which the cooling medium may pass.

References Cited in the file of this patent UNITED STATES PATENTS2,188,401 Crowley Jan. 30, 1940 2,646,647 Bamford et al. July 28, 1953FOREIGN PATENTS 707,949 Germany July 8, 1941

